Electric elevator system.



E. M. FRASER.

ELECTRIC ELEVATOR SYSTEM.

APPLICATION FILED APR. 28. 1914.

1,266,576. Patented May 21, 1918.

W/ ESSES l/VI/E/VTOR UNITED STATES PATENT OFFICE.

ETHELBERT M. FRASER, OF YONKERS, NEW YORK, ASSIGNOR TO GENERAL ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTRIC ELEVATOR SYSTEM.

Specification of Letters Patent.

. Patented May 21, 1918.

Application filed April 28, 1914. Serial No. 834,971.

To all whom it may concern Be it known that I, ETHELBERT M. FRASER, a citizen of the Dominion of Canada, residing at Yonkers, county of Westchester, and State of New York, have invented a new and useful Improvement in Electric Elevator Systems, of which the following is a specification.

My invention relates to an electric elevator system or hoisting apparatus, of the traction type, comprising two electric machines, each having two rotors, one of which rotors includes an armature and the other a field, said rotors being so connected that when operated one rotor of one machine will rotate in the same direction as one of the rotors of the other machine, and the other two rotors will rotate in directions the reverse of each other. In other words, when the system or apparatus is being operated three of the rotors will rotate in the same direction, while the fourth rotor will rotate in a direction the reverse of the other three. Such a system is not only shown herein but also in reissued United States Letters Patent No. 13,806, granted to me on October 13th, 1914, for an electric elevator system.

In the embodiment of my invention, as shown and described herein, my improved electric elevator system or hoisting apparatus comprises two electric machines, each having inner and outer rotors, the rotors of each machine magnetically and electrically coijperating with each other and providing an armature and a field, the outer rotors of the two machines being rigidly connected together, while the inner rotors are provided.

with pulleys which are connected together by a flexible connector in such a way that the inner rotors must rotate in directions the reverse of each other.

The objects of my invention will appear from the drawings and the detailed description to follow.

An electric elevator or hoisting system embodying the features of one embodiment of my invention is illustrated in the accompanying drawings forming a part of this specification, in which I The figure is a view partly in section of the two electric machines, the idler pulley 0r sheave, and the flexible connector.

- Referring to the drawings, the two electric machines 1 and 2 constitute a motorgenerator set. Machine 1 comprises an support the inner ends of the armature shafts 9, 10 rotatably j ournaled therein. The other ends of the armature shafts 9, 10 are rotatably journaled in the standards 11 and 12 respectively. The field structure 3 is rotatably mounted upon a projection of the standard 11 by means of a spider or endbell 13, 13, and the field structure 5 is rotatalbly mounted upon a projection of the standard 12 by means of the spider or endbell 14, 14. With this construction the armatures 4, 6 are rotatable in either direction, and the coupled field structures 3, 5 are also rotatable in either direction.

Upon the outer ends of the armature shafts 9 and 10 are suitably secured the pulleys or sheaves 15 and 16 respectively. The idler pulley or sheave 17 is suitably sup ported in the hanger 18 and arranged so as to rotate in either direction. The flexible connector preferably comprises a plurality of iron hoisting ropes 19 which engage the driven by one of the armatures, then to engage the idler pulley, and then over the other pulley so that the ends of the connector running to the 'car and counterweight will engage corresponding faces of the two pulleys driven by the armatures.

The car and counterweight are connected to the flexible connector 19, and the flexible connector 19 passes over and engages the pulleys or sheaves 15, 16 and 17 in the same manner as shown in my reissued Patent No.

13,806. The field magnets of machines 1 and 2 are electrically connected up in series and connected across the line or power mains, and the armatures 4, 6 are in multiple and connected across the line in thesame manner as shown in Fig. 3 of my reissued Patent No. 13,806. The system herein shown and described is also to be provided with the usual armature starting rheostat, a suitable fixed'resistance in the field circuits, and a plain field rheostat to vary the field strength of either motor.

The insertion of the yoke or spider 8 between the fields 3 and 5' is equivalent, mechanically and magnetically, to an extension of each field laterally until they meet. Accordingly, each field need only be suificiently large to carry the average flux flow, whereas if the fields are magnetically independent of each other, as in my reissued Patent No. 13,806, each field must be sufiiciently large to carry the maximum flux flow.

By the specific construction herein shown and described I am enabled to reduce the weight of the fields, as compared with the combined weight of the fields when mag netically independent of each other, thereby lessening the cost of manufacture.

By connecting the power-transmitting means to the armatures, which are intermittently rotated, instead of to the fields as 1n my reissued patent, not only is the mass of each intermittently-rotated number re duced in weight but the mass will be located nearer the axis of rotation thereby resulting in a further reduction in the amount of current required to operate my apparatus.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an electric elevator system, the combination of two electric machines, each having an inner and an outer rotor providing electrically and magnetically coiiperating field and armature, the outer rotors being coupled together and the inner rotors being connected toggther by a flexible connector whereby they will rotate in directions the reverse of each other.

2. In an electric elevator system, the combination of two electric machines, each having a rotatable armature and a rotatable field structure encircling said armature, said field structures being rigidly and magnetically coupled together so that they will rotate in unison and the arma ures being con nected together by a flexible connector so that they will rotate in directions the reverse of each other. 3. In an electric elevator system, the com-- bination of two electric machines, each having a rotatable armature and a rotatable field structure encircling said armature, said field structures being rigidly and magnetically coupled together and the armatures being connected together by a flexible connector so that they will rotate in directions the reverse'of each other, and power-operating members driven by said armatures.

4. In an electric elevator system, the combination with a car, of a counterweight, two electric machines, each having a rotatable armature and a rotatable field structure encircling said armature, said field structures being rigidlyand magnetically connected together, and a flexible connector for transmitting the reactions between the connected field structures and their respective cooperating armatures to move said car.

5. In an electric elevator system, the combination of two electric machines, each having a rotatable armature and a rotatable field structure encircling said armature, said field structures being rigidly and magnetically connected together, and a flexible connector driven by said armatures.

6. In an electric elevator system, the combination of two electric machines, each having a rotatable armature and a rotatable field structure encircling said armature, said field structures being rigidly and magnetically connected together,,of a pulley driven by each of said armatures, an independent idler pulley, and a flexible connector engaging all of said pulleys.

7 In an electric elevator system, the combination of two electric machines, each hav ing a rotatable armature and a rotatable field structure encircling said armature, said field structures beingv rlgidly and magnetically connected together, a pulley driven by each of said armatures, an idler pulley, and power-transmitting means engaging all of said pulleys.

. 8. In an electric elevator system, the combinati on with a car, of a counterwei ht, two electric machines having rotatab e field structures and rotatable armatures, said field structures being mechanically rigidly and magnetically connected together, a pulley driven by each of said armatures, an idler pulley, and a flexible connector connected at one end to said car and passing over one of the pulleys driven by one of said armatures thence to said idler pulley and engaging the same and thence in the opposite direction over the pulley driven by the other of said armatures and connected at its other end to said counterweight.

In witness whereof I sign this specification in the presence of two witnesses.

ETHELBERT M. FRASER. 

